Pediatric antiphospholipid syndrome: clinical and immunologic features of 121 patients in an international registry.
OBJECTIVE
The purpose of this study was to obtain data on the association of antiphospholipid antibodies with clinical manifestations in childhood and to enable future studies to determine the impact of treatment and long-term outcome of pediatric antiphospholipid syndrome.


METHODS
A European registry extended internationally of pediatric patients with antiphospholipid syndrome was established as a collaborative project of the European Antiphospholipid Antibodies Forum and Lupus Working Group of the Pediatric Rheumatology European Society. To be eligible for enrollment the patient must meet the preliminary criteria for the classification of pediatric antiphospholipid syndrome and the onset of antiphospholipid syndrome must have occurred before the patient's 18th birthday.


RESULTS
As of December 1, 2007, there were 121 confirmed antiphospholipid syndrome cases registered from 14 countries. Fifty-six patients were male, and 65 were female, with a mean age at the onset of antiphospholipid syndrome of 10.7 years. Sixty (49.5%) patients had underlying autoimmune disease. Venous thrombosis occurred in 72 (60%), arterial thrombosis in 39 (32%), small-vessel thrombosis in 7 (6%), and mixed arterial and venous thrombosis in 3 (2%). Associated nonthrombotic clinical manifestations included hematologic manifestations (38%), skin disorders (18%), and nonthrombotic neurologic manifestations (16%). Laboratory investigations revealed positive anticardiolipin antibodies in 81% of the patients, anti-beta(2)-glycoprotein I antibodies in 67%, and lupus anticoagulant in 72%. Comparisons between different subgroups revealed that patients with primary antiphospholipid syndrome were younger and had a higher frequency of arterial thrombotic events, whereas patients with antiphospholipid syndrome associated with underlying autoimmune disease were older and had a higher frequency of venous thrombotic events associated with hematologic and skin manifestations.


CONCLUSIONS
Clinical and laboratory characterization of patients with pediatric antiphospholipid syndrome implies some important differences between antiphospholipid syndrome in pediatric and adult populations. Comparisons between children with primary antiphospholipid syndrome and antiphospholipid syndrome associated with autoimmune disease have revealed certain differences that suggest 2 distinct subgroups.
Avcin
Tadej
T
Department of Allergology, University Children's Hospital, University Medical Center Ljubljana, Ljubljana, Slovenia. tadej.avcin@kclj.si
Cimaz
Rolando
R
Silverman
Earl D
ED
Cervera
Ricard
R
Gattorno
Marco
M
Garay
Stella
S
Berkun
Yackov
Y
Sztajnbok
Flavio R
FR
Silva
Clovis A
CA
Campos
Lucia M
LM
Saad-Magalhaes
Claudia
C
Rigante
Donato
D
Ravelli
Angelo
A
Martini
Alberto
A
Rozman
Blaz
B
Meroni
Pier Luigi
PL
D000293:Adolescent; D000367:Age Factors; D016736:Antiphospholipid Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D007223:Infant; D007511:Ischemia / Q000453:epidemiology; D008297:Male; D012042:Registries; D013927:Thrombosis / Q000453:epidemiology; D020246:Venous Thrombosis / Q000453:epidemiology / Q000235:genetics